1. Technical Field
The present invention relates generally to plug-type aircraft doors; and, more particularly, to improved actuating mechanisms for: (i) latching and unlatching such doors from both the interior and exterior of the aircraft; (ii) arming and disarming the escape slide deployment mechanism from the interior of the aircraft; and (iii), automatically disarming the escape slide deployment mechanism when the plug-type aircraft door is being opened from the exterior of the aircraft. In accordance with the invention, the actuating mechanisms for latching and unlatching the plug-type aircraft door are designed such that the interior and exterior actuating door handles are slaved together only when the door is to be opened from the exterior of the aircraft. However, when the door is to be opened from the interior of the aircraft, the interior and exterior actuating handles are not slaved to one another for simultaneous pivotal movement, thereby insuring that under emergency conditions when it is necessary to open an armed door and deploy the escape slide, movement of the interior actuating handle from the door latched position to the door unlatched position is not accompanied by simultaneous pivotal movement of the the exterior door handle; but, rather, the exterior handle remains flush with the outer skin of the aircraft fuselage where it cannot interfere with slide deployment and/or damage the slide during deployment.
2. Background Art
Conventional commercial airplanes are commonly provided with a multiplicity of ingress and egress openings in the aircraft fuselage with suitable doors being provided for closure of such openings. The doors vary widely in terms of their construction and operation. Commonly such doors are plug-type doors which are designed to fit into the opening when the doors are closed so as to form a substantially smooth continuous uninterrupted exterior skin surface. When such plug-type doors are opened, they move inwardly and upwardly into the aircraft fuselage and slide upwardly along tracks deployed on the interior of the fuselage with the door being received within the compartment immediately above the ceiling in the passenger cabin. In some instances, the doors are electrically operated; whereas in other instances, the doors are manually operated. However, most commercial air carriers today are reluctant to rely upon electrical actuating systems and therefore, insist that passenger doors be designed for manual operation.
Moreover, as is well known to those skilled in the art, commercial passenger airplanes are required to carry emergency evacuation equipment including escape slides that are associated with one or more of the ingress and egress openings in the aircraft fuselage. Commonly the escape slides are stowed within the plug-type doors and are designed to move with the doors when the slide deployment system is disarmed. When the slide deployment system is armed, the escape slides stowed within the doors are automatically attached to the passenger deck adjacent the fuselage opening. As a consequence, when the door is opened under emergency conditions while the emergency evacuation equipment is armed, as the door moves upwardly the slide (which is now affixed to the passenger deck) is withdrawn from the door and deployed.
The present invention relates to improvements in actuating mechanisms for manually operable plug-type aircraft doors of the foregoing character. An existing and known door construction and actuating apparatus therefor is disclosed in U.S. Pat. No. 4,125,235-Fitzgerald et al. The existing construction disclosed in that patent involves a plug-type aircraft door of the foregoing character having an escape slide normally stowed therein and wherein the door is designed to be manually raised and lowered. The actuating mechanisms for latching and unlatching the aircraft door from both the interior and exterior of the aircraft, together with the arming mechanisms, are mounted in the fuselage structure surrounding the door opening as opposed to being mounted within the door itself. As there described in greater detail, the interior and exterior door handles are slaved together for movement in unison irrespective of which handle is employed to latch or unlatch the door. Thus, when the aircraft door is unlatched from the interior of the aircraft, the exterior door handle pivots outwardly from its stowed position flush with the aircraft's exterior skin and, unfortunately, such movement represents an undesired hazard if the door is being opened under emergency conditions where the escape slide is to be deployed.